Hi,
This sounds like a common case of upset stomach. You are going to need to give him 1 tablespoon of Pepto Bismol per ten pounds of body weight. At his next feeding start him on a bland diet of boiled chicken and rice to settle his stomach down. You will need to feed this in small quantity's so she doesn't woof it down and make himself sick again.
You should also start him on unflavored pedialyte to replace the electrolytes he is losing from the vomiting.Dehydration is a serious issue with dogs and the Pedialyte will prevent this. If he is still unable to hold down the Pedialyte or small amounts of the bland diet he will need to see his vet today. Dogs that go without eating are susceptible to a drop in their blood sugar which will make the issue worse.
If he becomes lethargic or you notice blood in the stool or vomit I would advise a physical examination by his vet. If he is not feeling better in 24 hours or gets worse I would recommend a examination by his vet.
Walter
Breeder
Breeder and pet health consultant. Have spent a number of years with dog rescue, training and health